;-NRLF 


American  Society  of  Municipal 
Improvements,  1915 


Specifications  for 

Creosoted  Wood  Block  Paving 

[These  specifications  have  not  been  adopted,  but  are  printed  for  information  and 
discussion  at  the  convention  at  Newark,  N.  J.,  Oct.  9-13,  1916.] 


These  specifications  will  be  modified  from  time  to  time 
to  keep  them  fully  up  to  date.  Suggestions  as  to  modifi- 
cations or  additions  are  solicited  and  should  be  sent  to 
the  Secretary,  or  to  Ellis  R.  Button,  City  Hall,  Minneap- 
olis, Minn.,  Chairman  of  the  Sub-Committee  on  Specifi- 
cations for  Wood  Block  Paving,  and — 


GEORGE  W.  TILLSON 

Boro  Hall,  Brooklyn,  N.  Y. 
Chairman  of  General  Committee  on  Standard  Specifications 


COPYRIGHTED,  1916 

Any  municipality  which  is  represented  in  the  membership  of  the  society  by  one  or  more 
City  Officials  will  be  given  free  permission  to  use  these  specifications  or  any  part  of  them 
upon  application  to  the  Secretary. 


PUBLISHED  BY  THE  SOCIETY 
CHARLES  CARROLL  BROWN,  Secretary 

702  WULSIN  BUILDING 
INDIANAPOLIS,  INDIANA 


REPORT    OF    SUB-COMMITTEE    ON    WOOD    BLOCK 
PAVING  SPECIFICATIONS. 

The  following  specifications  for  wood  block  paving  were  presented 
by  A.  W .  Dow,  for  the  Sub-Committee  on  Wood  Block  Paving 
Specifications,  to  the  Committee  on  Standard  Specifications,  and  were 
presented  as  information,  by  the  General  Committee,  to  the  Society 
on  October  14,  1915. 

SPECIFICATIONS  FOR  CREOSOTED  WOOD  BLOCK  PAVING. 
Timber. 

The  wood  to  be  treated  shall  be  southern  yellow  pine,  Norway 
pine,  Douglas  fire  or  tamarack.  Only  one  kind  of  wood  to  be  used 
in  one  contract.  The  blocks  must  be  cut  from  a  good  grade  of  timber, 
and  must  be  well  manufactured,  full  size,  square  butted  and  square 
edged,  free  from  the  following  defects:  checks,  unsound,  loose  or 
hollow  knots,  knotholes,  worm  holes,  thru  shakes  and  round  shakes 
that  show  on  the  surface. 

In  yellow  pine  timber  there  shall  be  not  less  than  four  (4)  annual 
rings  in  any  one  inch  measured  radially  from  the  pitch  center. 
Wherever  in  any  one  inch  there  are  less  than  six  (6)  annual  rings 
to  the  inch,  the  summer  wood  shall  average  not  less  than  25  per  cent. 
All  measurements  are  to  be  made  on  a  section  of  wood  cut  out  per- 
pendicular to  the  grain.  The  blocks  in  each  charge  must  average 
80  per  cent  of  heart  wood,  and  no  one  block  shall  be  accepted  that 
contains  less  than  50  per  cent  heart  wood. 

Size  of  Blocks. 

The  blocks  shall  be  from  five  to  ten  inches  long,  but  shall  average 

eight  inches ;  they  shall  be  * inches  in  depth.     They  shall  be 

from  three  to  four  inches  in  width,  but  in  any  one  city  block  all  of 
them  must  be  of  uniform  width.  A  variation  of  1/16  inch  shall  be 
allowed  in  the  depth  and  width  of  the  blocks  from  that  specified. 


*NOTB. — The  committee  recommends  blocks  4  inches  in  depth  for  heavy  traffic 
streets;  blocks  3%  inches  in  depth  for  medium  to  light  traffic  streets;  for  light 
traffic  streets  blocks  3  inches  in  depth  may  be  used,  but  where  3-inch  blocks  are 
used  no  blocks  shall  be  longer  than  8  inches. 


Preservative. 

The  preservative  shall  be  wholly  derived  from  coal  gas  tar  or 
coke  oven  tar,  and  shall  comply  with  the  following  requirements: 

1st:  The  specific  gravity  shall  be  not  less  than  1.06  nor  more 
than  1.12  at  38°  C. 

2nd:  Not  more  than  3  per  cent  shall  be  insoluble  by  continuous 
hot  extraction  with  benzol  and  chloroform. 

3rd:  On  distillation  which  shall  be  made  exactly  as  afterwards 
described,  the  distillate,  based  on  water  free  oil,  shall  be  within  the 
following  limits: 

Up  to  210°  C,  not  more  than       5%, 

Up  to  235°  C,  .not  more  than  30%, 

Up  to  315°  C,  not    less    than  35%    nor  more   than   70%, 

Up  to  355°  C.,  not    less    than  65%. 

4th:  The  specific  gravity  of  the  distillate  between  235°  C.,  and 
315°  C.,  shall  be  not  less  than  1.02  at  38°  C,  compared  with  water 
at  15.5°  C.  The  specific  gravity  of  the  distillate  between  315°  C. 
and  355°  C.  shall  be  not  less  than  1.08  at  38°  C.  compared  with 
water  at  15.5°  C. 

5th:  The  specific  viscosity  at  82°  C.,  when  taken  in  an  Engler 
viscosimeter  shall  not  exceed  1.3.  The  term  specific  viscosity  shall 
mean  the  number  of  seconds  found  for  the  sample  tested  divided  by 
the  number  of  seconds  for  water  at  20°  C.,  as  given  in  the  official 
certificate  for  the  viscosimeter  used. 

6th :  The  oil  shall  not  contain  more  than  3  per  cent  of  water. 
Oil  samples  taken  by  the  inspector  from  the  treating  tank  during  the 
progress  of  the  work  shall  at  no  time  show  an  accumulation  of  more 
than  2  per  cent  of  foreign  matter,  such  as  sawdust  and  dirt,  and  due 
allowance  shall  be  made  for  all  foreign  matter,  either  water  or 
material  insoluble  in  benzol  and  chloroform,  by  injecting  an  addition- 
al quantity  of  oil  into  the  block. 

Treatment. 

The  blocks  shall  be  treated  in  an  air  tight  cylinder,  with  the  pres- 
ervation heretofore  specified.  They  shall  first  be  subjected  to  live 
steam  at  a  temperature  between  220°  F.  and  240°  F.,  for  not  less 
than  two  hours,  after  which  they  shall  be  subjected  to  a  vacuum  of 

3 


342937 


not  less  than  twenty  inches  and  held  for  at  least  ten  minutes.  The 
temperature  of  the  blocks  shall  be  maintained  between  150°  F. 
and  240°  F.  While  the  vacuum  is  still  on,  the  preservative  oil, 
heated  to  a  temperature  of  between  180°  F.  and  200°  F.,  shall  be 
admitted,  and  the  pressure  gradually  applied  to  the  cylinder  until 
a  sufficient  amount  of  the  preservative  oil  has  been  forced  into  the 
block.  After  this,  if  so  desired,  a  supplemental  vacuum,  with  or 
without  steam,  may  be  applied.  At  the  completion  of  the  treatment 
each  charge  of  blocks  shall  contain  not  less  than  an  average  of  18 
pounds  of  water-free  oil  per  cubic  foot  of  wood.  Not  more  than 
10  per  cent  in  excess  of  the  amount  specified  shall  be  allowed.  The 
blocks  after  treatment  shall  show  satisfactory  penetration  of  the 
preservative,  and  in  all  cases  the  sap-wood  must  be  thoroly  treated 
thruout.  To  determine  this,  at  least  25  blocks  shall  be  cut  up  from 
each  charge,  and  if  more  than  4  per  cent  of  the  blocks  show  un- 
treated sap-wood,  the  charge  shall  be  retreated  or  rejected.  After 
re-treating,  the  charge  shall  be  again  subjected  to  the  same  inspection. 

The  surface  of  the  blocks  after  treatment  shall  be  clean  and  free 
from  any  deposit  of  oil  or  foreign  substance. 

All  blocks  that  are  imperfect  or  that  have  been  injured  in  the 
process  of  treating  shall  be  rejected. 

Handling  Blocks  After  Treatment. 

After  the  blocks  have  been  treated  and  before  they  are  laid,  care 
must  be  taken  to  protect  them  as  much  as  possible  from  drying  out. 
They  must  at  all  times  be  closely  piled  when  stacked  on  the  street. 
All  blocks  must  be  thoroly  wet,  either  while  piled  on  the  street  before 
laying  or  while  being  laid,  as  directed  by  the  Engineer. 

Inspection. 

All  material  and  processes  used  in  the  manufacture  of  the  blocks 
shall  be  inspected  at  the  plant  of  the  manufacturer,  who  shall  equip 
his  plant  with  all  the  necessary  gages,  appliances  and  facilities  to 
enable  the  inspector  to  satisfy  himself  that  the  requirements  of  the 
specifications  are  fulfilled.  He  shall  allow  the  inspector,  or  other 
authorized  representatives,  to  inspect  all  material  at  all  parts  of  the 
plant. 

4 


After  delivery  upon  the  street  the  blocks  shall  be  subjected  to  a 
further  inspection,  and  all  imperfect  blocks  shall  be  rejected  and 
removed  from  the  street  by  the  contractor. 

Foundation. 

The  base  shall  be  of  concrete  made  in  accordance  with  the  speci- 
fications for  concrete  paving  foundation  and  shall  be* inches 

in  thickness.  At  no  place  shall  the  surface  of  the  finished  concrete 
vary  more  than  one-half  inch  from  the  given  grade.  The  concrete 
foundation  shall  be  cleaned  and  swept  and  shall  be  thoroly  dampened 
immediately  in  advance  of  the  spreading  of  the  cushion  course. 

.Cushion,  (a)  Mortar  Bed. 

Upon  the  concrete  foundation  shall  be  spread  a  layer  of  dry  mortar 
one  inch  in  thickness  and  made  of  one  part  of  Portland  cement  and 
three  parts  of  sand,  the  intention  being  to  produce  a  granular 
mixture  which  may  be  raked  to  the  desired  grade.  Only  sufficient 
water  shall  be  added  to  this  mixture  to  insure  a  proper  setting  of  the 
cement.  The  dry  mortar  shall  be  thoroly  mixed  and  shall  be  spread 
in  place  on  the  foundation  by  means  of  a  template  immediately  in 
advance  of  the  laying  of  the  blocks,  to  such  a  thickness  that  when  the 
blocks  are  set  and  properly  bedded  in  the  mortar  their  tops  shall 
conform  accurately  to  the  finished  grade  of  the  roadway. 

Cushion,   (b)  Sand. 

Upon  the  concrete  foundation  shall  be  spread  a  cushion  of  sand, 
one  ( 1 )  inch  in  thickness.  The  sand  cushion  shall  be  struck  by 
templates  to  a  surface  parallel  to  the  grade  and  contour  of  the  finish- 
ed pavement  in  such  a  manner  that  when  the  blocks  are  set  and  prop- 
erly bedded  in  the  sand,  the  tops  shall  conform  accurately  to  the 
finished  grade  of  the  pavement.  The  sand  used  in  this  cushion  shall 
all  pass  thru  a  quarter  (^)  inch  screen  and  must  contain  between 
ten  (10)  and  twenty-five  (25)  per  cent  of  loam  or  clay. 

Laying  the  Blocks. 

Upon  the  bed  thus  prepared  the  blocks  shall  be  carefully  set  with 
the  fiber  of  the  wood  vertical,  in  straight  parallel  courses,  generally 

*NOTE. — The  committee  recommends  that  the  concrete  bed  be  at  least  6  inches 
tn  thickness  and  under  heavy  traffic  8  inches  to  9  inches  in  thickness. 


at  right  angles  to  the  curb,  leaving  a  space  next  to  the  curb  for  the 
expansion  joint*. 

The  blocks  shall  be  laid  by  setting  them  closely  together  on  the 
mortar  bed  and  no  joint  shall  be  more  than  J^"  in  width.  Nothing 
but  whole  blocks  shall  be  used  except  in  starting  a  course,  or  in  such 
other  cases  as  the  city  may  direct;  and  in  no  case  shall  the  lap  joint 
be  less  than  2".  Closures  shall  be  carefully  cut  and  trimmed  by 
experienced  men.  The  portions  of  the  block  used  for  closures  must 
be  free  from  checks  or  other  fractures  and  the  cut  end  must  have  a 
surface  perpendicular  to  the  top  of  the  block  and  cut  to  the  proper 
angle  so  as  to  give  a  close,  tight  joint. 

After  the  blocks  are  placed  they  shall  be  rolled  parallel  and 
diagonal  to  the  curb  by  a  steam  roller  weighing  between  four  and 
seven  tons,  until  the  surface  becomes  smooth  and  is  brought  truly 
to  the  grade  and  contour  of  the  finished  pavement.  The  rolling 
shall  be  completed  before  the  mortar  bed  has  set.  All  mortar  that 
has  set  before  the  blocks  are  in  place  and  rolled  shall  be  discarded 
and  replaced  by  fresh  mortar. 

Filler,    (a)    Sand. 

After  the  rolling  is  completed,  the  joints  between  the  blocks  shall 
be  filled  by  sweeping  dry,  clean  sand  into  them,  after  which  the 
surface  shall  be  covered  to  a  depth  of  about  ^"  with  fine  sand. 
This  sand  is  to  be  left  upon  the  pavement  for  such  a  time  as  may  be 
directed  by  the  city,  after  which  it  shall  be  swept  up  and  taken  away 
by  the  contractor. 

Filler,   (b)   Bituminous. 

After  the  rolling  is  completed,  the  joints  between  the  blocks  shall 
be  filled  with  a  bituminous  filler,  specified  hereafter.  The  filler  shall 
be  brought  to  the  proper  temperature  and  poured  into  the  joints; 
any  filler  on  the  surface  of  the  pavemnt  must  be  spread  as  thin  as 
possible  by  means  of  squeegees. 

After  the  joints  are  filled,  as  prescribed,  the  surface  shall  be  com- 
pletely covered  by  a  thin  coat  of  clean,  coarse,  dry  sand,  and  a 
similar  coating  of  sand  shall  be  spread  over  the  pavement,  if  required 
by  the  Engineer,  before  the  acceptance  of  the  pavement.  The  filler 

•NOTE. — The  committee  recommends  expansion  joints  %  inch  in  width  at 
each  curb  for  streets  up  to  30  ft.  in  width  ;  1  inch  in  width  for  streets  between 
30  and  50  ft.  in  width  and  1%  inches  in  width  for  streets  over  50  ft.  in  width. 


used  shall  be  a  straight  run   residue  obtained   from  the  distillation 
of  coal  tar  and  shall  comply  with  the  following  requirements: 

1st.  The  melting  point  shall  be  not  lower  than   135°   F.,  nor 
higher  than  145°  F. 

2nd.   It  shall  contain  between  22  per  cent  and  37  per  cent  of 
free  carbon  insoluble  in  hot  chloroform  and  benzol. 

3rd.  Its  specific  gravity  at  77°  F.,  shall  not  be  less  than   1.24 
nor  more  than  1.32. 

4th.  The  specific  gravity  of  the  distillate  up  to  355°   C.,  shall 
not  be  less  than  1.07  at  38°   C,  compared  with  water  at   15.5°   C. 

"  Thermometers  In  Kettles. 

The  kettles  in  which  the  filler  is  heated  on  the  street  shall  be 
equipped  with  approved  thermometers,  and  the  pitch  shall  be  heated 
to  a  temperature  of  not  less  than  255°  F.,  nor  more  than  300°  F., 
and  shall  be  poured  when  at  a  temperature  between  these  limits. 

METHODS  OF  SAMPLING  AND  TESTING  PRESERVATIVE. 
Sampling.     Continuous  Drip  Sample. 

Wherever  the  oil  is  being  loaded  or  discharged  by  means  of  a 
pump  the  following  method  shall  be  used : 

The  pipe  line  thru  which  the  material  is  being  pumped  shall  be 
tapped  on  the  discharge  side  of  the  pump,  preferably  in  a  rising 
section  of  the  pipe  line.  The  sample  shall  be  taken  by  means  of  a 
^-inch  pipe  extending  half  way  to  the  center  of  the  main  pipe,  and 
the  inlet  of  the  ^-inch  pipe  shall  be  turned  to  face  the  flow  of  the 
liquid.  This  pipe  shall  discharge  into  a  barrel  or  drum  of  50  to  100 
gallons  capacity,  and  the  plug  cock  regulated  so  as  to  secure  a  contin- 
uous uniform  stream  during  the  entire  pumping  of  the  shipment. 
The  barrel,  or  preferably  the  iron  drum,  should  be  provided  with  a 
small  steam  coil,  sufficient  to  keep  the  contents  thoroly  liquid.  The 
temperature  shall  not  exceed  120°  F.  The  contents  of  the  barrel 
or  drum  shall  be  very  thoroly  agitated  and  small  samples  for  testing 
taken  immediately.  The  amount  of  the  drip  sample  collected  shall 
be  not  less  than  1  gallon  to  1,000  gallons  of  material  handled,  ex- 
cepting in  the  case  of  large  boat  shipments,  where  a  maximum  of 
100  gallons  will  suffice. 


Storage  Tank  Samples. 

In  sampling  from  storage  it  is  necessary  to  secure  samples  from 
different  levels,  and  where  possible  this  may  be  done  by  means  of 
small  outlet  cocks  at  regular  intervals  from  the  top  to  the  bottom  of 
the  storage  tank.  In  such  cases,  about  1  gallon  of  tar  or  oil  shall  be 
drawn  from  each  outlet  cock  and  thoroly  mixed  and  a  portion  taken 
for  testing.  The  stream  from  each  cock  shall  always  be  allowed 
to  flow  for  sufficient  length  of  time  to  empty  the  outlet  pipe  and 
nipple  before  commencing  to  collect  the  sample. 

When  tanks  have  no  outlet  cocks  a  vessel  having  a  string  attached 
to  the  cork  may  be  lowered  to  measured  depth  representing  a  number 
of  the  different  levels  iii  the  tank  and  the  cork  removed  when  the 
vessel  has  reached  the  proper  level.  These  samples  shall  be  combined 
for  an  average  as  above. 


STANDARD    DISTILLATION    TEST 
CREOSOTE     OIL 

TESTING. 

Distillation   Test.     Apparatus  for  Distillation   Test. 

(a)  Retorts:  This  shall -be  a  tubulated  Jena  glass  retort  of  the 
usual  form  with  a  capacity  of  250  to  290  c.c.  The  capacity  shall  be 
measured  by  placing  the  retort  with  the  bottom  of  the  bulb  and  the 
end  of  the  off-take  in  the  same  horizontal  plane,  and  pouring  water 


into  the  bulb  thru  the  tubulature  until  it  overflows  the  off-take. 
The  amount  remaining  in  the  bulb  shall  be  considered  its  capacity. 
(Fig.  1.) 

(b)  Condenser  Tube:     Any  suitable  form  of  glass  tubing  may  be 
used;  a  convenient  one  is  shown  in  Fig.  1. 

(c)  Shield:     An  asbestos  shield  as  shown  in  Fig.  2,  shall  be  used 
to   protect   the   retort   from   air   currents   and   to   prevent   radiation. 
This  may  be  covered  with  galvanized  iron,  as  such  an  arrangement 
is  more  convenient  and  more  permanent. 

(d)  Receivers:      Erlenmeyer    flanks   of   50    to    100    c.c.    capacity 
are  most  convenient  form. 

(e)  Thermometers:     The   thermometer  shall   be  of    glass,    well 
annealed,    and   shall   undergo   no   serious   change   at   the   zero   point 
when  heated  up  to  400°   C.     The  space  above  the  mercury  column 
shall  be  filled  writh  gas,  either  carbon  dioxide  or  nitrogen,  and  the 
thermometer  shall  have  an  expansion  chamber  at  the  top. 

The  scale  shall  read  from  0  to  400°  C.,  in  graduations  of  1°  C., 
which  shall  be  etched  on  the  stem. 

The  tip  of  the  thermometer  shall  carry  a  ring  for  the  purpose  of 
attaching  tags.  The  thermometer  shall  have  the  following  di- 
mensions : 

Total  length,  375  mm.;  tolerance,  10  mm. 
Bulb  length,  14  mm.;  tolerance  1  mm. 
Distance  from  zero  mark  to  bottom  of  bulb,  30  mm. ;  tolerance, 

4  mm. 

Scale  length  from  zero  mark  to  400°C.,  295  mm. ;  tolerance,  5  mm. 
Diameter  of  stem,   7  mm. ;  tolerance,   1   mm. 
Diameter  of  bulb,  6  mm. ;  tolerance,    1   mm. 

When  standardized  the  accuracy  of  such  standardization  should 
be  as  follows: 

Up  to  200°C., to  the  nearest  0.5°C. 

200   to   300°C., to   the   nearest    1.0°C. 

300  to  360°  C to  the  nearest   1.5°C. 

Assembling   for  Distillation    Test. 

The  retort  shall  be  supported  on  a  tripod  or  rings  over  twro 
sheets  of  20-mesh  gauze,  6  inches  square.  It  shall  be  connected 

9 


to  the  condenser  tube  by  a  tight  cork  joint.  The  thermometer 
shall  be  inserted  thru  a  cork  in  the  tubulature  with  the  bottom 
of  the  bulb  J^  inch  from  the  surface  of  the  oil  in  the  retort.  The 
exact  location  of  the  thermometer  bulb  shall  be  determined  by 
placing  a  central  rule  graduated  in  divisions  not  exceeding  1/16 
inch  back  of  the  retort  when  the  latter  is  in  position  for  the  test, 
and  sighting  the  level  of  the  liquid  and  the  point  for  the  bottom 
of  the  thermometer  bulb.  The  distance  from  the  bulb  of  the  ther- 
mometer to  the  outlet  end  of  the  condenser  tube  shall  be  not  more 
than  24  nor  less  than  20  inches.  The  burner  should  be  protected 
from  draughts  by  a  suitable  shield  or  chimney.  (Fig.  1.) 

Distillation  Test. 

Exactly  100  g.  of  oil  shall  be  weighed  into  the  retort,  the  appar- 
atus assembled  and  heat  applied.  The  distillation  shall  be  con- 
ducted at  the  rate  of  at  least  one  drop  and  not  more  than  two  drops 
per  second,  and  the  distillate  collected  in  weighed  receivers.  The 
condenser  tube  shall  be  warmed  whenever  necessary  to  prevent-  ac- 
cumulation of  solid  distillates.  Fractions  shall  be  collected  at  the 
following  points:  Up  to  210°  C. ;  up  to ,235°  C. ;  235  to  315°  C. ; 
315  to  355°  C.  The  receivers  shall  be  changed  as  the  mercury  passes 
the  dividing  temperature  for  each  fraction.  The  last  receiver  shall 
be  removed  at  355°  C.,  and  drainage  from  the  condenser,  etc., 
shall  not  be  considered  as  part  of  the  fraction.  For  weighing  the 
receivers  and  fractions,  a  balance  accurance  to  at  least  0.05  g.  shall 
be  used.  During  the  progress  of  the  distillation  the  thermometer 
shall  remain  in  its  original  position.  No  correction  shall  be  made 
for  the  emergent  stem  of  the  thermometer. 

When  any  measurable  amount  of  water  is  present  in  the  distillate 
it  shall  be  separated  as  nearly  as  possible  and  reported  separately, 
all  results  being  calculated  on  a  basis  of  dry  oil.  When  more  than 
2  per  cent  of  water  is  present,  water-free  oil  shall  be  obtained  by 
separately  distilling  a  larger  quantity  of  oil,  returning  to  the  oil  any 
oil  carried  over  with  the  water,  and  using  dried  oil  for  the  final 
distillation.  A  copper  tar  still  is  a  convenient  means  of  obtaining 
water-free  oil. 

Specific  Gravity   Test.     Apparatus  for  Specific  Gravity   Test. 

(a)  Hydrometer:  The  hydrometer  shall  be  of  the  form  and 
dimensions  shown  in  Fig.  3. 

10 


(b)    Cylinder:  The  cylinder  shall  be  of  the  form  and  dimensions 
shown  in  Fig.  4. 


-*      »  €>  MM 


HYDROMETER 
FIG. 


CYLINDER 
FIG.  -4. 


Specific  Gravity   Test. 

A  standardized  hydrometer  (Fig.  3)  shall  be  used.  A  set  of  two 
ranges,  1.00  to  1.08  and  1.07  to  1.15  will  suffice.  The  reading  should 
preferably  be  taken  at  38°  C.  (100°  F.),  because  at  this  tempera- 
ture almost  all  oils  are  completely  fluid. 

Before  taking  the  specific  gravity  the  oil  in  the  cylinder  should 
be  stirred  thoroly  with  a  glass  rod,  and  this  rod  when  withdrawn 
from  the  liquid  should  show  no  solid  particles  at  the  instant  of 
withdrawal.  Care  should  be  taken  that  the  hydrometer  does  not 
touch  the  sides  or  bottom  of  the  cylinder  when  the  reading  is  taken, 
and  that  the  oil  surface  is  free  from  froth  and  bubbles.  If  the 
specific  gravity  is  determined  at  a  higher  temperature  than  desired, 
correction  should  be  made  by  adding  0.0008  to  the  reading  for  each 
degree  Centigrade  excess  of  temperature. 

The  sub-committee  on  wood  block  paving  specifications  for  igi6 
was  instructed  to  gather  data  regarding  specifications  for  oil  and 
to  present  a  report  by  February  I,  1916,  if  possible,  to  be  printed  in 
the  proceedings,  but  the  committee  was  appointed  too  late  to  com- 
plete its  work  and  the  proceedings  were  printed  without  the  report. 

Invitation  was  extended  by  the  General  Committee  to  those  so 
desiring  to  send  suggestions  to  the  committee  regarding  provisions 

11 


desired  in  the  specifications  and  the  following  are  printed  as  being 
the  suggestions  received  by   the  secretary   up   to  February    I. 

The  three  members  of  the  new  committee,  E.  R.  Dutton,  Chair- 
man, A.  W .  Dow  and  H.  Von  Schrenk,  recommend  the  specifica- 
tions printed  above. 

P.  C.  Reilly  recommends  the  following  specifications  for  improved 
creosote  oil: 

IMPROVED  CREOSOTE  OIL. 

1.  The  oil  shall  be  obtained  by  the  distillation  of  coal  tar  and 
shall  consist  wholly  of  such  distillate  from  coal  tar  as  will  comply 
with  the  following  requirements: 

2.  The  oil  shall  have  a  specific  gravity  of  not  less  than  1.12  nor 
more  than  1.14  at  38°C. 

3.  When  the  oil  is  subjected   to  distillation  the  distillates  shall 
be  as  follows: 

Distillate  to  250°C.  not  over  1  per  cent. 
Distillate  to  315°C.  not  over  15  per  cent. 
Distillate  to  355 °C.  not  over  40  per  cent. 

4.  The  residue  above  355 °C.  shall  be  of  a  soft  waxy  nature  at 
25  °C.     When  a  drop  is  heated  on  white  filter  paper  until  it  is  ab- 
sorbed by  the  paper,  the  spot  formed,  when  viewed  by  transmitted 
light,  shall  be  of  a  yellowish  amber  color. 

5.  When  25  grams  of  the  oil  are  placed  in  an  open  pressed  tin 
box   approximately  2l/2    inches   in   diameter   and    ^4    inch   deep   and 
kept  at  a  temperature  of  49°C.  (120°F.)  it  shall  not  lose  more  than 
5  per  cent  by  evaporation  in  72  hours. 

Tests. 

The  residue  above  355 °C.  shall  have  a  specific  gravity  of  not  less 
than  1.17  at  25°C. 

The   residue   above   355°C.   shall   have   a   specific   gravity   of   not 
less  than  1.17  at  25°C. 

The   residue    above   380° C.   shall   be   of    a   soft   waxy   nature   at 
25  °C. 

The  specific  gravity  of   the   fraction   of  the   distillate   400 °C.   to 
420°C.  shall  be  not  less  than  1.12  at  38°C. 

12 


Sulphonation :  When  the  following  fractions  of  the  distillate, 
315°C.  to  380°C.  and  380°C.  to  420°C.,  are  subjected  to  the  sul- 
phonation  test,  neither  of  them  shall  contain  more  than  2  per  cent 
of  unsaponical  oil  in  that  particular  fraction. 

And  I  would  suggest  that  any  specification  adopted  should  be  so 
drawn  as  to  exclude  the  use  of  coal  tar  or  any  other  kind  of  tar 
from  the  preservative  oil,  and  that  the  preservative  consist  of  the 
highest  grade  of  creosote  oil. 

W ' .  H.  Fulweiler,  Chemist  of  the  United  Gas  Improvement  Co., 
proposes  the  following: 

SPECIFICATIONS  FOR  -PRESERVING  OIL  FOR  USE  IN  WOOD  BLOCK 
PAVING  TREATMENT. 

(1)  Preservative  oil  shall  be  a  product  of  water  gas  tar  and  be 
free  from  admixture  of  other  crude  or  unrefined  tars. 

(2)  The  specific  gravity  at  38°  C.,  compared  with  water  at  the 
same  temperature  shall  be  between   1.11   and   1.14. 

(3)  Material  insoluble  by  hot  continuous  extraction  with  benzol 
or  chloroform  shall   not   exceed   2%   by  weight. 

(4)  Distillation  to  210°   C.,  shall  not  exceed     3%  by  weight. 
Distillation  to  235°  C.,  shall  not  exceed   10%  by  weight. 
Distillation  to  315°  C,  shall  not  exceed  40%  by  weight. 
Distillation  to  355°  C.,  shall  not  be  less  than  25%. 

(5)  Specific    gravity    of    the   distillate   at  38°    C.,   compared    to 
15.5°  between  235°  C.,  and  315°  C,  should  not  be  less  than  .96, 
nor  more  than    1.00. 

C.  N.  Forrest,  Chemist  of  the  Barber  Asphalt  Paving  Co.,  for- 
wards the  following: 

WOOD  PAVING  BLOCKS. 

The  representatives  of  The  Barber  Asphalt  Paving  Company 
have  opposed  the  adoption  of  the  specifications  for  wood  paving 
blocks  which  were  presented  at  the  annual  meetings  of  the  American 
Society  for  Municipal  Improvements  in  1914  and  in  1915,  because 
that  portion  of  such  specifications  which  defined  the  character  of 

13 


the  preservative  oil  excluded  materials  of  equal  value,  from  a  service 
point  of  view,  which  are  more  generally  available  than  the  specific 
oil  called  for. 

This  company  is  not  a  producer  or  distiller  of  tar  of  any  kind, 
but  is  merely  conducting  a  wood  treating  plant  and  purchases  its 
oil  or  tar  employed  for  saturating  blocks  and  other  timber  entirely 
from  outside  sources.  It  has  treated  large  quantities  of  wood  blocks 
with  coal  tar  oil  of  essentially  the  same  character  as  that  proposed 
in  the  specifications,  as  well  as  with  water  gas  tar  and  with  creosote 
and  various  other  combinations  which  may  have  been  called  for. 
There  is  ample  evidence  of  the  sufficiency  of  other  oils  and  tars  than 
the  one  proposed,  and  in  view  of  the  impossibility  of  including  all 
of  them  in  a  single  specification  without  making  its  requirements 
too  general  to  be  effective,  we,  therefore,  suggest  that  the  require- 
ments for  the  preservative  be  described  under  two  separate  heads  as 
follows : 

Type  "A"— Coal-Tar  oil. 
Type  "B"— Water-Gas  Tar  oil. 

The  preservative  proposed  for  adoption  by  the  committee  is 
described  as  a  coal  tar  oil,  but  could  be  a  mixture  of  coal-tar  and 
water-gas  tar  products  as  far  as  any  of  the  tests  mentioned  in  the 
specifications  are  concerned. 

We  do  not  criticise  it  as  being  unsuitable  for  the  purpose,  but 
water-gas  tar  is  equally  suitable  and  has  the  advantage  of  being 
more  available  and  of  lower  cost  to  all  concerned.  We,  therefore, 
propose  the  following  specification  for  a  preservative  consisting  of 
water-gas  tar  as  an  alternative  of  the  coal  tar  preservative  pro- 
posed by  the  committee: 

The   preservative   shall   be   refined   water-gas   tar,    and   shall 
comply  with   the   following   requirements: 

1.  The  specific  gravity  shall  be  not  less  than    1.12  nor  more 
than    1.14   at  38  °C.,   referred   to  water   at   the  same   tem- 
perature. 

2.  Not  more  than  2.0%   shall  be  insoluble  by  hot  extraction 
with  benzol  and  chloroform. 

3.  On    distillation    which    shall    be    made    as    hereinafter    de- 
scribed,  the  distillate,   based   upon  water-free  oil,   shall   be 
within  the  following  limits: 

14 


Up  to.210°C.,    not   more   than     5.0% 

Up  to   235  °C.,   not  more   than    15.0% 

Up  to   315°C.,   not  more   than   40.0% 

Up  to   355°C,    not   less    than   25.0% 

4.  The  specific  gravity  of  the  total   distillate  below  355°C., 
shall  not  be  less  than  1.00  at  38°C.,  referred  to  water  at 
the  same  temperature. 

5.  The  oil  shall  not  contain  more  than  2.0%  water  and  due 
allowance  shall  be  made   for  all  water  and  insoluble   for- 
eign  matter   it   may   contain   by   injecting  a   corresponding 
additional  quantity  into  the  blocks. 

The  Barber  Asphalt  Paving  Company  has  treated  millions  of 
wood  blocks  with  Water-Gas  Tar  of  the  above  character  and  such 
blocks  have  been  in  practical  service  as  long  as  coal  tar  blocks,  as 
both  kinds  were  introduced  about  ten  years  ago. 

In  1908  about  22,000  square  yards  of  water-gas  tar  blocks  were 
laid  in  Boston,  Pittsburg,  Harrisburg,  New  London,  Zanesville,  and 
Havana,  Cuba,  and  in  subsequent  years  have  been  laid  in  quantity 
in  a  great  variety  of  locations  without  a  single  failure.  There  is, 
therefore,  indisputable  evidence  of  the  suitable  character  of  the  pre- 
servative described  in  our  proposed  specification  for  water-gas  tar, 
and  such  a  specification  will  not  admit  a  tar  of  unsuitable  character 
for  the  purpose,  nor  one  which  has  been  mixed  with  petroleum 
distillates  or  residues  of  any  kind. 

The  above  recommendations  are  made  in  response  to  a  request  of 
the  Committee  on  Specifications  at  the  Dayton  meeting  for  such 
recommendations  before  February  1st,  1916. 

J.  W .  Howard,  Consulting  Engineer  on  roads  and  pavements, 
New  York  City,  recommends  the  following  specification: 

The  preservative  used  must  be  a  distillate  creosote  oil  of  above 
1.03  sp.  grav.  at  38°  C.  (100°  F.),  containing  less  than  1%  of 
matter  insoluble  in  benzol  by  hot  extraction.  It  shall  be  waterproof, 
antiseptic,  containing  at  least  10%  of  crystallizable  naphthalene, 
and  at  least  15%  of  the  stable  anthracene  oil.  When  distilled  as 
described  in  Bulletin  No.  65,  American  Railway  Engineering  and 
Maintenance-of-Way  Association,  the  total  distillate  on  basis  of 

15 


water-free  oil  up  to  150°  C.  (302°  F.),  shall  not  exceed  1%;  the 
total  up  to  200°  C.  (392°  F.),  shall  not  exceed  5%.  The  distilla- 
tion shall  be  continued  to  315°  C.  (600°  F.),  and  the  residue  then 
remaining,  when  cooled  to  25°  C.  (77°  F.),  shall  be  soft  and  easily 
indented  with  the  finger.  The  creosote  oil  used  shall  be  a  distillate 
made  from  coal-tar  or  a  combination  of  distillates  from  coal-tar  and 
water-gas  tar,  provided  the  oil  produced  meets  all  the  above  tests 
of  qualities  needed  for  thoroly  preserving  wood. 


14  DAY  USE 

RN  TO  DESK  FROM  WHICH  BORROWED 
LOAN  DEPT 


ubject  to  immediate  recall. 


JAN  8  3  1959 


LD  21A-50m-9,'58 
(6889slO)476B 


.General  Library 
University  of  Calif  or 


Berkeley 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


